Impact of Human Activity and Climate on Nitrogen in Agriculture

Abstract

High concentrations of gases containing nitrogen in the air and different nitrogen forms in soils, plants and water pose a threat both to the environment and to human health. Here I review the impact of various factors on the content of nitrate, nitrite, ammonium, organic and total nitrogen, urease and nitrate reductase in soils and plants. I also review impacts on ammonia, nitrous oxide, nitrogen dioxide and nitric oxide in the atmosphere. The strongest effect on concentrations of gases is the type of animals producing the gases. A weaker dependency is the distance from a farm, and the lowest effect is the type of plant species. The highest concentration of NH3 and N2O came from cattle (56.1 and 42.3 μg m−3), whereas the lowest – from camels (0.3 and 0.5 μg m−3), respectively. The following dependency prevailed: the longer the distance from animal farms, the lower the concentrations of ammonia.

Higher emissions of ammonia (92.0%) and nitrous oxide (74.8%) were found to come from urea in a crop field, whereas lower from calcium ammonium nitrate applied to grassland (1.6% of NH3) and from ammonium salts used in a crop field (0.1% of N2O). Similar tendencies were observed for NO. Total emission of ammonia was the highest when resulting from the spreading of waste (36%), whereas the lowest volatilization from grazing / outdoors (8%). The older the animals, the higher the NH3 loss. The highest organic nitrogen concentration was noted after the application of pig slurry manure (3.5%) and the lowest after applying cattle and pig farmyard manure (FYM) (2.3%) above ryegrass field. The highest amounts of net nitrogen were found in Melilotus alba, whereas the lowest in Poa pratensis. A total nitrogen concentration also depended on the type of crops. Its level was higher in Vicia faba (48.71%) and the lowest in grained winter rye cereals (14.96%).

Notes

Acknowledgments

The investigations were conducted at the Institute for Agricultural and Forest Environment, Polish Academy of Sciences in Poznań, Poland within the framework of the NitroEurope Integrated Project No. 017841 titled “The nitrogen cycle and its influence on the European greenhouse gas balance”, which was a part of the Sixth Framework Programme for Research and Technological Development of the European Union.

Huber C, Kreutzer K (2002) Three years of continuous measurements of atmospheric ammonia concentrations over a forest standat the Höglwald site in southern Bavaria. Plant Soil 240:13–22CrossRefGoogle Scholar